A city on the water

Another sequence that Matt is particularly proud of is the flotilla of boats that survivors end up on, thinking that they’ll be safe from zombies here – though as Matt darkly hints, “we’ll see”. The shots of the flotilla are composited from three main elements: clean plates of the Royal Navy’s RFA Argus hospital ship that Matt spent a day filming (with four marker boats around 1,000 feet away to give its scale when tracking), footage shot on the Argus when moored and hundreds of CG boats that would make up the rest of the flotilla. Cinesite also had to add people to the ships, and create CG versions of the Royal Navy helicopters taking off from the Argus when bad weather prevented this being filmed.

“When we came to shoot Brad on the ship, the ship was moored in Falmouth, [which is] quite an enclosed place,” says Matt. “It also turned out to be Falmouth Regatta week – so there'd be the brass band outside the chip shop and the Red Arrows flying overhead.

“With all our hard work, you'll hopefully never really know that Brad's getting out of the boat in front of Stan's chip shop with the Girl Guides bobbing for apples [next to it].”

Censored VFX

During the course of the interview, Matt discussed pushing the boundaries of how inhuman – and frightening – the team at Cinesite could make the zombies, but their efforts to scare and horrify the audience were constrained by the film’s targeted PG-13 rating in the US (and 15 in the UK). However, there were a few little tricks that Matt let me in on that allowed the film to show a zombie apocalypse without upsetting the MPAA and BBFC.

While it’s obvious that you’re allowed to show more violent things happening to inhuman creatures like zombies than you can to human characters – what’s most important it seems is the colour of their blood.

“It's an important thing, the colour of blood,” says Matt. “Zombies have black blood because it’s cool, and because you can have black stuff flying out of them without upsetting the censor.

“One of the first features I supervised was a Bruckheimer movie called King Arthur, which we'd originally made as an 18/'hard R'.  It was decided to change it to be a PG-13 – but we had the most gory footage: arrows in the eyes, arrows everywhere.

“One of the things were able to do that helped a lot was to hue shift the blood from red to brown – and once we’d removed arrows from people's eyes too – [we had a PG-13 version].”

Another choice that allowed Cinesite to get to smash zombies around a bit more is that, as the film progresses, the zombies’ flesh becomes more fibrous and withered – and therefore less gory when torn apart.

“Those decisions were made because aesthetically they look cool,” says Matt, “but also mindful that MPAA would probably go for that because it looks like some twigs snapping rather someone having their legs chopped off.”

Matt left the interview for the final day of VFX work on Tom Clancy franchiser Jack Ryan, mentioning that the red-to-black blood trick might get some work on that film too. You can see more before-and-after shots of Cinesite's VFX work on World War Z below.